MCMCB Pro
M05.861

M05.861Other rheumatoid arthritis with rheumatoid factor of right knee

Billable / specific codeICD-10-CMright

M05.861 is a billable, specific ICD-10-CM code for other rheumatoid arthritis with rheumatoid factor of right knee. It is valid for submission on a claim.

Risk adjustment

M05.861 risk-adjusts. Under the CMS-HCC V28 model it maps to this category:

  • HCC 93 Rheumatoid Arthritis and Other Specified Inflammatory Rheumatic Disorders0.617 RAF

Coefficient shown for the Community Non-dual Aged segment. A higher HCC in the same hierarchy will suppress this one, so capturing it does not always add score.

Medicare coverage

M05.861 is named in 40 Medicare coverage policies 34 listing it as supporting medical necessity, and 6 listing it as NOT covered. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

  • A58865Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
  • A58893Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
  • A59374Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered
  • A59434Billing and Coding: Amniotic and Placental-Derived Product Injections and/or Applications for Musculoskeletal Indications, Non-Woundnot covered

Related codes at this level

Codes that share M05.86. If M05.861 is not quite right, the correct code is usually one of these.

Questions about M05.861

Is M05.861 a billable ICD-10-CM code?
Yes. M05.861 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does M05.861 sit in the tabular list?
Diseases of the musculoskeletal system and connective tissue (M00-M99), in the block Inflammatory polyarthropathies (M05-M14).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.